AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

History of AFNI updates  

|
May 01, 2003 11:33AM

Hello Gang:

Again, having a cell size of n=1 does NOT necessarily preclude one from
conducting ANOVA. In particular, for the 2 factor ANOVA mixed effects model
(i.e., 3dANOVA2 -type 3), the F-test for factor A main effect is calculated:

F(A) = MSA / MSAB, where MSAB = SSAB / (a-1)(b-1).

Here, a = #levels of Factor A (say, 4), and b = #levels of Factor B (say, 14).
Hence, the denominator degrees of freedom for the F-statistic is given by:
df = (a-1)(b-1) = 3*13 = 39.

For more details, please see the documentation in file 3dANOVA.ps.

Doug Ward
Subject Author Posted

3dANOVA question from April 24

jennifer April 29, 2003 11:59AM

Re: 3dANOVA question from April 24

B. Douglas Ward April 30, 2003 04:40PM

Re: 3dANOVA question from April 24

jennifer May 01, 2003 10:37AM

Re: 3dANOVA question from April 24

Gang Chen May 01, 2003 10:44AM

Re: 3dANOVA question from April 24

B. Douglas Ward May 01, 2003 11:09AM

Re: 3dANOVA question from April 24

jennifer May 01, 2003 11:26AM

Re: 3dANOVA question from April 24

B. Douglas Ward May 01, 2003 12:08PM

Your 2nd approach

Gang Chen May 01, 2003 10:59AM

Re: Your 2nd approach

B. Douglas Ward May 01, 2003 11:33AM

I got your point

Gang Chen May 01, 2003 11:47AM